For example, Japanese Laid-Open Patent Publication No. 2003-106581 and product catalog “DAIKIN air purifier, HIKARI CRIALE”, DAIKIN INDUSTRIES, Ltd., August, 2006 disclose conventional typical air purifiers. In the conventional air purifiers, an air purifying filter having an electrostatic dust collecting filter portion and a deodorizing filter portion is provided in front of a motor driving fan that has a rotary shaft extending in the depth direction of the air purifier, that is, in a front-and-rear direction. This increases the size of the conventional air purifier in its depth direction. Therefore, when being used in a room, the conventional air purifier occupies undesirably large space.